Spinal Cord Injury 1 Flashcards
SCI most common cause
MVC
Falls is next
Mechanism of Injury
Hyperflexion
Hyperextension
Compression
Excessive lateral bending or rotation
Mechanism of Injury - Hyperflexion
Post ligament tears and dislocates
Complete SCI in about 1/3 of flexion injuries
Mechanism of Injury - Hyperextension
Anterior ligament tears
Mechanism of Injury - compression
Crushing of vertebrae
Bony fragments can go into spinal cord and cause damage
75% chance of complete SCI
Mechanism of Injury - Trauma - Transection causes
Glia disrupted
Spinal cord tissue torn
Can be caused by penetrating trauma, blunt trauma, bony fragment, disc herniation
Mechanism of Injury - Compression causes
Violent shaking or direct blow
Temporary loss of function
Mechanism of Injury - Contusion
Glial tissue and spinal cord surface are intact
May have loss of central grey and white matter
Created cavity with white matter rim at periphery
Mechanism of Injury - Vascular Injury
Suspect if discrepancy between clinical neuro deficit and level of spinal injury
Mechanism of Injury - Vascular injury - examples
Lower cervical dislocation compresses vertebral arteries within spinal foramina of vertebrae
Thrombosis
Pathophysiology - Primary injury
Damage that occurs immediately at time of injury
Spared tissues and axons may remain and are important in recovery
Pathophysiology - Primary injury - Forces
Compression Contusion Shear Penetrating Gun shot wound that does not enter the spinal cord
Pathophysiology - Secondary injury
Begins within minutes
Evolves over hours
Can be from:
Ischemia, hypoxia, inflammation, edema, electrolyte disturbances
Pathophysiology - Secondary Injury - examples of electrolyte distrubances
Intracellular Ca inc
Extracellular K inc
Na permeability inc
Pathophysiology - Secondary injury - Blood flow changes
Within 2 hours Dec spinal cord blood flow Rapid swelling at injury level Pressure on cord becomes higher than venous pressure Ischemia Necrosis
Pathophysiology - Secondary injury - Edema occurs
Within hours of injury
First and injury site and then spreads to adjacent and distant segments
Clinical Presentation
Depend on mech of injury
Typically pain at injury site, but not always
Often associated brain and systemic injuries
About 1/2 of traumatic SCI are cervical
Treatment of SCI - initial treatment is what
C spine immobilization!
CABs
Full spine immobilization
Clearing airways with pt with SCI
Modified jaw thrust to make sure to keep C spine in line
SCI - Consults
Neurosurgeon Orthopedics Trauma specialist General surgeon Others as needed An patient will be admitted
SCI - imaging
X ray
CT
MRI
SCI - Clinical localization - Complete cord injury
Transection of cord that can come from severe compression, or extensive vascular dysfunction
Complete loss of sensory and motor function below level of lesion
SCI - Clinical localization - Complete cord injury - ASIA grade
A
SCI - Clinical localization - Complete cord injury - Acute stages
Absent reflexes No response to plantar stimulation Flaccid mm tone Male - priapism Urinary retention and bladder distension
SCI - Clinical localization - Incomplete cord injury
Contusions, edema, bony fragments
Partial loss of sensory and motor function below level of lesion
SCI - Clinical localization - Incomplete cord injury - ASIA grade
B to D
SCI - Clinical localization - Incomplete cord injury - sensation and motor function
Various degrees of muscle motor function
Various degrees of sensation in dermatomes
Usually sensation is preserved more than motor function
SCI - Neurological level and completeness of injury with recovery
More incomplete the injury = more favorable the potential for recovery
Esp. on initial eval at 72 hrs to 1 wk after injury
SCI - Deficits determined by neurologic levels/lesions
Tetra/Quad - spinal cord segment C1-C8
Para - Thoracic, lumbar, or sacral segments
Spinal Cord Syndrome - Central Cord Syndrome
Damage central part of SC
Peripheral fibers not affected
Spinal Cord Syndrome - Central Cord Syndrome - often caused by
Often from cervical hyperextension with pre existing cervical spondylosis
Spinal Cord Syndrome - Central Cord Syndrome - s/s
More severe motor impairments in UE then LE
Bladder dysfunction
Variable sensory loss below injury level
Spinal Cord Syndrome - Central Cord Syndrome - s/s with tracts
Loss of pain and temp at site of injury and surrounding dermatome due to crossing of spinothalamic
Dermatome above and below will have intact pain and temp
Vibration and proprio often spared
Spinal Cord Syndrome - Anterior Cord Syndrome -
Often due to loss of blood supply from anterior spinal artery
Spinal Cord Syndrome - Anterior Cord Syndrome - Corticospinal tract
Weakness and reflex changes
bilateral loss motor function
Spinal Cord Syndrome - Anterior Cord Syndrome - Spinothalamic
Pain and temp loss bilaterally
Spinal Cord Syndrome - Anterior Cord Syndrome - Tactile, position, and vibratory sense
Normal
Spinal Cord Syndrome - Anterior Cord Syndrome - Caused by
Flexion injuries
Intervertebral disc herniation
Spinal cord infarction
Radiation myelopathy
Spinal Cord Syndrome - Posterior Cord Syndrome - Causes
MS, Friedreich ataxia, tabes dorsalis
Tumors, cervical spondylotic myelopathy
Spinal Cord Syndrome - Posterior Cord Syndrome - Corticospinal
If actue - weakness, muscle flaccidity, hyporeflexia
If chronic - mm hypertonia, hyperreflexia
Spinal Cord Syndrome - Posterior Cord Syndrome - s/s
Loss of proprioception - wide based gait ataxia
Loss of vibratory sensation
Bladder dysfunction
Paresthesias
Spinal Cord Syndrome - Brown Sequard syndrome
Unilateral involvement
Dorsal column
CST, spinothalamic tract